September weather forecastTumtum, WA
September
Weather in September
September, the first month of the autumn in Tumtum, is also an agreeable month, with an average temperature varying between 72.7°F (22.6°C) and 46.6°F (8.1°C).Temperature
A shift in the average high-temperature occurs in September, reducing from a moderately hot 84°F (28.9°C) in August to a pleasant 72.7°F (22.6°C). A sharp reduction from the daytime highs is witnessed during September, with nighttime temperatures averaging a low of 46.6°F (8.1°C).Humidity
The average relative humidity in September in Tumtum is 53%.Rainfall
In Tumtum, in September, during 7 rainfall days, 0.63" (16mm) of precipitation is typically accumulated. In Tumtum, during the entire year, the rain falls for 124.9 days and collects up to 17.44" (443mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.51" (13mm) of snow. In Tumtum, during the entire year, snow falls for 69.2 days and aggregates up to 42.99" (1092mm) of snow.Daylight
In Tumtum, the average length of the day in September is 12h and 33min.On the first day of the month, sunrise is at 6:10 am and sunset at 7:30 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:31 pm PDT.
Sunshine
In Tumtum, the average sunshine in September is 10.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 4 during September translates into the following guidance:
Undertake precautions - Obligation exists to protect against skin and eye damage. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Experience reduced UV exposure by about half when donning a wide-brim hat. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Tumtum, WA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is August (84°F).
The month with the lowest average high temperature is December (31.3°F).
- Average low temperature in September: 46.6°F
The month with the highest average low temperature is August (54.3°F).
The coldest month (with the lowest average low temperature) is December (20.3°F).
Average pressure in September
Tumtum, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The months with the lowest atmospheric pressure are June and August (29.91"Hg).
Average wind speed in September
Tumtum, WA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is April (5.6mph).
The calmest month (with the lowest average wind speed) is December (4mph).
Average humidity in September
Tumtum, WA
- Average humidity in September: 53%
The month with the highest relative humidity is January (92%).
The month with the lowest relative humidity is August (43%).
Average rainfall in September
Tumtum, WA
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is January (2.4").
The driest month (with the least rainfall) is August (0.31").
Average rainfall days in September
Tumtum, WA
- Average rainfall days in September: 7 days
The month with the highest number of rainy days is March (16.2 days).
The month with the least rainy days is August (5.1 days).
Average snowfall in September
Tumtum, WA
- Average snowfall in September: 0.51"
The month with the highest snowfall is January (13.23").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Tumtum, WA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (16.9 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Tumtum, WA
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 10h and 6min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in September
Tumtum, WA
- Average sunshine days in September: 21.3 days
The month with the most sunshine days is July (24.2 days).
The month with the least sunshine days is March (9.7 days).
Average UV index in September
Tumtum, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are February, November and December (UV index 1).
Average cloud cover in September
Tumtum, WA
- Average cloud cover in September: 22
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Tumtum, WA
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The month with the lowest visibility is January (3mi).





